An Assistant Garda Commissioner is seeking overturn what he says is his "bizarre", "unlawful" and "unfair" suspension from duty pending the outcome of an investigation by the Garda Síochána Ombudsman Commission (GSOC).

An Assistant Garda Commissioner is seeking overturn what he says is his "bizarre", "unlawful" and "unfair" suspension from duty pending the outcome of an investigation by the Garda Síochána Ombudsman Commission (GSOC).

John Fintan Fanning was suspended on January 3 last in "flagrant breach of fair procedures". He is also very concerned about the manner in which his suspension was "leaked" to the media, Paul McGarry SC, for Mr Fanning, told the High Court on Friday.

The case, against the Garda Commissioner, arose from a "very unusual and very serious set of circumstances".

The GSOC investigation - into a protected disclosure made by a rank and file Garda - concerned two "incredibly straightforward" issues of fact and the issue was how they could ever have lead to any decision to suspend, counsel said.

Nor did Mr Fanning accept it was a "holding suspension".

Mr Fanning's retirement is imminent and the suspension was "calculated to cause him damage".

Information in the media about his suspension, and the timing of such reports, meant the information could only have come from Garda headquarters, counsel said.

Some media reports had used the word "corruption" when that is nowhere found in any of the investigation documents and is "false", he added.

In a sworn statement, Mr Fanning said he was shocked on reading a news report on the Irish Times website at 4am on January 3 which said a senior Garda officer was under investigation over alleged serious misconduct.

He was concerned a suspension was imminent and was informed shortly after 9.30am he had been suspended from duty.

In his proceedings, he wants orders lifting his suspension pending the outcome of his challenge, restraining the Commissioner communicating "false"" information concerning him and directing the Commissioner to co-operate with the GSOC investigation. He is also claiming damages.

When the matter came ex parte - one side only represented - before Ms Justice Leonie Reynolds on Friday, the judge said the best approach was to grant permission to serve short notice of the proceedings on the Commissioner and return the matter to Tuesday.

Mr Fanning, due to retire in August after almost 39 years in the force, has held several high-profile posts, including chief superintendent of the Dublin South Central Division and regional commander for the Northern and Eastern Regions.

He said his career "speaks for itself" and he has an "unblemished disciplinary record in my almost 39 years of service."

He became aware on December 3 GSOC had received a protected disclosure made by a rank and file Garda and he was asked by GSOC to provide certain information within 30 days.

He provided that by December 20 and that same day GSOC served a notice stating it had received a complaint under the Protected Disclosures Act and had commenced a public interest investigation.

The notice informed him the complainant Garda alleged that, on a date in November 2017, he was contacted directly by another Garda officer and told he was no longer on a specialist firearms course following an intervention by Mr Fanning.

The second allegation concerned an incident in December 2017 involving an assault and the Garda claimed he was the victim in the incident.

The complainant claimed he was initially placed on restricted non-confrontational duties and later served with the force's disciplinary documentation. He claimed he was suspended from duty, following a recommendation by Mr Fanning, and treated as a suspect.

Mr Fanning said it was not unusual for GSOC to receive complaints and he was not concerned as the matter related to two separate internal management matters that were "relatively minor and straightforward".

He was "somewhat taken aback" at the narrative description of the two complaints and the classification by GSOC the offence under investigation was misconduct in public office which he believed has never been prosecuted here.

He had no role in the selection process for the firearms course but had reported concerns by various officers a Garda who had not passed the course selection process was intending to attend it.

He said the complainant's second allegation referred to an investigation into an allegation the complainant Garda had been involved in an assault on a female at an hotel.

His own involvement was in the usual way of managing the file and forwarding it to his superiors, including his recommendation the Garda be suspended.